As is well known by those familiar with diesel engines and their performance, diesel fuels generally do not possess the ability to lubricate surfaces and to minimize the wear of the injectors of diesel engines.
Great concern has been expressed by original equipment manufacturers over the wear seen in the upper cylinder of internal combustion engines, particularly, diesel engines. An example which illustrates this concern is the Ford Tornado Diesel Engine test which measures the extent of "scuffing" and "polishing" seen in the upper cylinder. It is apparent that lubricating oils can influence this wear, especially on the downward stroke when the oil has contacted the cylinder wall where the motion will occur.
If the fuel can be made to perform as a better lubricant it is possible to obtain further improvement. Since there is an upward compression stroke with the diesel fuel present, the more of a protective lubricant this fuel is, the better the performance of the diesel engine.
The fuel is injected prior to the compression stroke. During the compression stroke, the fuel is the lubricant for the motion since it is in contact with the cylinder wall which will undergo the contact motion. This is prior to the ignition of the fuel. It is reasonable to believe that the majority of wear seen in the upper cylinder comes from the upward motions of the piston since the cylinder wall section is not lubricated relative to the downward motion where oil should have had contact.
Thus, an object of this invention is to provide a diesel fuel having improved wear resistant properties. Other objects will be apparent from the following discussion.